Rafferty et al. Archives of Public Health (2017) 75:22 DOI 10.1186/s13690-017-0190-z
RESEARCH
Open Access
Factors influencing risky single occasion drinking in Canada and policy implications Ellen Rafferty1, William Ian Andrew Bonner1, Jillian Code1, Keely McBride1, Mustafa Andkhoie1, Richa Tikoo1, Stephanie McClean1, Colleen Dell2, Michael Szafron1 and Marwa Farag1*
Abstract Background: Misuse of alcohol, including single risky occasion drinking (RSOD) is associated with a number of health, social and economic consequences. While research demonstrates that many factors contribute to individuals’ drinking practices, little is known about risk factors that contribute to RSOD in the Canadian population. The objectives of this study are to examine the patterns of RSOD in Canada, to identify factors associated with RSOD, and to explore policy implications. Methods: The Canadian Community Health Survey (CCHS) 2009–2010 annual component was used to conduct all the analyses in this paper. We used two models: (1) a binary logistic regression model, and (2) a multinomial logistic regression model, to identify factors that were significantly associated with our dependent variables, RSOD engagement and frequency of RSOD, respectively. Results: Daily smokers were 6.20 times more likely to engage in frequent RSOD than those who never smoke. Males were 4.69 times more likely to engage in risky RSOD. We also found significant associations between the frequency of RSOD and Province/Territory of residence, income and education, marital status and perceived health status. Finally, stress was associated with engaging in infrequent RSOD. Conclusions: Our finding associating daily smoking with risk alcohol intake specifically suggests the possibility of combining public health interventions for both. The study findings also indicate that education is a protective factor, further supporting the role of education as a major determinant of health. The significant provincial variation we found also point to the need to study this issue further and understand the links between provincial level policies and RSOD. Keywords: Risky single occasion drinking RSOD in Canada, Health policy, Stress, Smoking, Alcohol, Education, Social determinants, Provinces
Background From a public health perspective, alcohol consumption is a challenging issue to address. Controversy existed in the research community whether low levels of alcohol consumption have protective effects, and if these effects outweigh known harms; however, there is a growing consensus in the literature that the positive effects of alcohol consumption have been overestimated in the past [1–4]. Defining low-risk consumption has proved methodologically difficult, resulting in a variety of guidelines for low-risk alcohol intake across countries [5]. * Correspondence: [email protected] 1 School of Public Health, University of Saskatchewan, 104 Clinic Place, Saskatoon, SK S7N 2Z4, Canada Full list of author information is available at the end of the article
Likewise, alcohol misuse represents a wide spectrum of terms, from exceeding low-risk guidelines to alcohol dependence. A glossary of terms used in this article is outlined in Table 1. Despite variation in how different organizations define and convey low-risk drinking, it is clear that the misuse of alcohol, including risky single occasion drinking (RSOD), is associated with a number of negative health, social, and economic consequences [6, 7]. Direct health implications associated with alcohol misuse include dependency, liver cirrhosis, organ damage, diabetes, cardiovascular disease, and various types of cancer [7, 8]. Furthermore, impaired judgement, impaired driving ([9]), injury, suicide, and risky sexual behaviour may be prompted by high levels of alcohol consumption,
© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Rafferty et al. Archives of Public Health (2017) 75:22
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Table 1 Glossary of Terms Associated with Alcohol Consumption Alcohol abuse
Is a pattern of drinking that results in harm to one’s health, interpersonal relationships, or ability to work [62].
Alcohol dependency
Dependency on alcohol, also known as alcohol addiction and alcoholism, is a chronic disease. The signs and symptoms for alcohol dependence include a strong craving for alcohol, continued use despite repeated physical, psychological, or interpersonal problems and the inability to limit drinking [62].
Binge drinking
A pattern of alcohol consumption that brings the blood alcohol concentration level to 0.08% or more. This pattern of drinking usually corresponds to 5 or more drinks on a single occasion for men or 4 or more drinks on a single occasion for women, generally within about 2 h [26].
Excessive alcohol use
Excessive drinking, or excessive alcohol use includes binge drinking, heavy drinking, any alcohol use by people under the minimum legal drinking age, and any alcohol use by pregnant women [63].
Heavy drinking
For men heavy drinking is typically defined as consuming 15 drinks or more per week. For women, heavy drinking is typically defined as consuming 8 drinks or more per week [63].
Heavy episodic drinking
Defined by the World Health Organization (WHO) as 60 or more grams of pure alcohol on at least one single occasion at least monthly [15].
Risky drinking
Women having more than 3 drinks or men having more than 4 drinks on any single occasion once per month or more often [64].
Risky single occasion drinking (RSOD)
Having X number of standard drinks or more (X+) on one occasion. This definition may vary across countries by number of drinks as well as grams of alcohol per drink [65]. This article uses 5 or more drinks regardless of sex to define RSOD, based on the CCHS classification, which is equivalent to consuming 70 g or more of pure alcohol on one single occasion.
suggesting there may be broader health and social repercussions [7, 10]. In Canada, the most recent comprehensive economic analysis of alcohol-related costs was conducted in 2006 using data from 2002, and estimated that a total of CAD 14.6 billion was spent that year on direct and indirect costs [11, 12]. These costs are associated with healthcare, law enforcement, and productivity losses [7, 12]. Direct healthcare costs alone accounted for CAD 3.3 billion in spending in 2002 [7, 12]. More recently in 2013, the costs of Fetal Alcohol Spectrum Disorder (FASD) in Canada alone totalled approximately CAD 1.8 billion dollars [13] In contrast, the societal and healthcare costs of excessive alcohol use in the United States have been estimated at USD 223.5 billion and 24.5 billion, respectively [14]. Worldwide, alcohol abuse accounted for approximately 3.3 million deaths and 139 million disability-adjusted life years (DALYS) due to injury and morbidity [15]. Inhabitants of the North American region drank 8.4 l of pure alcohol per capita in 2010, 35% higher than the world average (6.2L) and second only to the European region (10.9 L). Among current alcohol drinkers in the Americas, the prevalence of heavy episodic drinking is 22%, again second only to Europe (22.9%). In the United States, the prevalence of monthly binge drinking defined in the article as 5+ drinks for men, 4+ for women in one occasion is approximately 17% [16]. A substantial proportion of these alcohol-related harms are associated with populations who exceeded low-risk alcohol guidelines, which is determined by quantity and/or frequency of alcohol use [7, 14, 17]. As the frequency of RSOD increases, the likelihood of negative health and social consequences increases [7, 17]. In addition, there is some evidence from the United States
which indicates that moderate drinkers contributed to the majority of RSOD episodes ([18]). Research shows that a number of economic, cultural, and historical factors contribute to individuals’ drinking practices [1, 19]. Data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and the National Survey on Drug Use and Health (NSDUH) demonstrated associations between early initiation of drinking (before the age of 21), age of 20–29 years, enrollment in college, being male and an increased engagement in RSOD, [1, 20]. However, it appears the gender gap is decreasing among younger cohorts [8]. In general, the factors that impact alcohol consumption have not been well explored within a Canadian context. Of particular interest may be how location of residence influences alcohol consumption in Canada, as provincial and territorial (P/T) jurisdiction over alcohol policy has created a patchwork of liquor regulations throughout the country [19, 21]. Studying provincial variations in alcohol consumption may provide insight into the impact of public policy, along with other cultural and socio-political differences, on RSOD. Furthermore, a deeper understanding of the risk factors that contribute to RSOD with respect to P/T may help guide relevant and informed alcohol related policies for each P/T. Although experts agree that alcohol consumption can lead to negative health, social and economic consequences, defining low-risk intake has proved challenging for researchers and organizations [5, 12, 22]. Both volume and patterns of alcohol use can lead to separate risks, and studies have varied in their assessment of risk, with some focused on dose–response curves, while others focused on alcohol-attributable fractions [5]. Grams of pure alcohol per standard drink varies widely
Rafferty et al. Archives of Public Health (2017) 75:22
worldwide and portion sizes served often differ from the standard drink [5]. These debates added to the complexity for P/T governments and non-profit organisations to determine Canada’s Low Risk Alcohol Drinking Guidelines and communicate them to the public. In 2011, the National Alcohol Strategy Working Group (NASWG) recommended that, based on the available evidence, no more than two drinks should be consumed on most days for women (28 g of ethanol) and no more than three a day for men (42 g of ethanol) [23–25]. Similarly, the guidelines recommend that over the duration of a week, women should consume less than 10 drinks and men less than 15 (140 and 210 g of pure alcohol, respectively) [23]. The CCSA defines risky drinking as “women having more than 3 drinks or for men more than 4 drinks on any single occasion once per month or more often” [23]. In contrast, the Canadian guidelines surrounding the definition of low-risk drinking are stricter compared to guidelines in the United States. For women, the National Institute on Abuse and Alcoholism (NIAA) [26] decrees that low-risk drinking consists of no more than 3 drinks per day and 7 per week (42 and 98 g of pure alcohol, respectively), whereas for men the guideline is 4 and 14 respectively (56 and 196 g of pure alcohol, respectively) [26]. European guidelines vary widely by country, and in response to this, recent practice principles from the Joint Action Reducing Alcohol Related Harm (RARHA) in Europe and the Center for Addiction and Mental Health (CAMH) have attempted to identify a standard definition of risk. They indicate that a level of alcohol intake of 10 g or less per day would result in an alcohol attributed death rate of below 1 in 100, and provide this as a suggested maximum for low risk drinking [27, 28]. This would equate with less than one standard drink per day in Canada, where one standard drink contains approximately 14 g of pure alcohol [24, 25]. The overall purpose of this study is to explore the pastyear prevalence of RSOD in Canada and the factors associated with any RSOD and frequency of RSOD in Canada. Understanding the underlying factors contributing to RSOD in Canada will help guide the development of more effective policy interventions to curtail high-risk consumption. The two research questions developed were: 1) What factors determine the likelihood of individuals engaging in any RSOD over the past 12 months? 2) What factors determine the likelihood of engaging in frequent RSOD? We defined infrequent RSOD as (past-year occurrence of drinking 5+ drinks (70+ grams alcohol) once a month or less) and frequent RSOD as (past-year occurrence of drinking 5+ drinks (70+ grams alcohol) more than once a month).
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Methods The Canadian Community Health Survey (CCHS) 2009–2010 annual component was used to conduct all the analyses in this paper ([29]). The sample size of this survey was 124,188. The response rate for the outcome variable of interest “How often in the past 12 months have you had 5 or more drinks on one occasion?” was 74.3%. Since logistic regression modeling uses listwise exclusion of missing values, the sample size of the regression models and descriptive statistics was 68,440. The sample was weighted using the survey weights provided by CCHS as instructed by Statistics Canada [30]. Descriptive statistics were conducted in SPSS Version 22.0 and regression modeling conducted using SAS 9.4 software. The alpha was set at 0.05. Dependent variables
The CCHS captured individual’s alcohol consumption through the original question “How often in the past 12 months have you had 5 or more drinks on one occasion?” R (18) [29]. As this is the only measure for alcohol consumption in the CCHS, we drew on the work of Thomas [19] and defined occasional any RSOD conservatively as having 5 or more drinks on one occasion in the past 12 months, infrequent RSOD as having 5 or more drinks on one occasion once or less than once a month and frequent RSOD as having 5 or more drinks on one occasion more than once a month [19]. In Canada, one standard drink contains approximately 14 g of pure alcohol, therefore RSOD in this case would be defined as having 70 g of alcohol in one sitting [24, 25]. Based on these definitions, we created two dependent variables: (1)RSOD which has two categories (binary outcome variable). ‘Yes’ if individual engaged in any RSOD in the past 12 months and ‘no’ if the individual did not engage in RSOD in the past 12 months. (2)Frequency of RSOD (multinomial outcome variable) which has three categories: i. No RSOD in the past 12 months ii. Infrequent RSOD: Over the past year, engaging in RSOD once a month or less iii. Frequent RSOD: Over the past year, engaging in RSOD more often than once a month Independent variables
Based on the relevant literature, we were able to identify independent variables likely associated with risky drinking, including age, sex, marital status, education status, income, employment, smoking status, self-perceived health, and self-perceived life stress [7, 31, 32]. As Thomas [19] identified, there is substantial provincial variation in alcohol consumption across Canada, and so
Rafferty et al. Archives of Public Health (2017) 75:22
we included the P/T variable as a geographic marker, as well as an indication of alcohol price and other regulatory policies. This comparison is possible as price (e.g., taxation) and regulation of alcohol differ by P/T. The P/ T variable also stands to represent other historical, socio-political and cultural factors that may be present within jurisdictions. Age groups were categorized based on Thomas et al. [19]. Employment status was grouped as “employed last week” and “unemployed last week” to see the effect of employment status on RSOD, and was categorized based on the CCHS question, “Are you an employee or self-employed?” Total household income was captured and analyzed in increments of CAD 20,000 from
RESEARCH
Open Access
Factors influencing risky single occasion drinking in Canada and policy implications Ellen Rafferty1, William Ian Andrew Bonner1, Jillian Code1, Keely McBride1, Mustafa Andkhoie1, Richa Tikoo1, Stephanie McClean1, Colleen Dell2, Michael Szafron1 and Marwa Farag1*
Abstract Background: Misuse of alcohol, including single risky occasion drinking (RSOD) is associated with a number of health, social and economic consequences. While research demonstrates that many factors contribute to individuals’ drinking practices, little is known about risk factors that contribute to RSOD in the Canadian population. The objectives of this study are to examine the patterns of RSOD in Canada, to identify factors associated with RSOD, and to explore policy implications. Methods: The Canadian Community Health Survey (CCHS) 2009–2010 annual component was used to conduct all the analyses in this paper. We used two models: (1) a binary logistic regression model, and (2) a multinomial logistic regression model, to identify factors that were significantly associated with our dependent variables, RSOD engagement and frequency of RSOD, respectively. Results: Daily smokers were 6.20 times more likely to engage in frequent RSOD than those who never smoke. Males were 4.69 times more likely to engage in risky RSOD. We also found significant associations between the frequency of RSOD and Province/Territory of residence, income and education, marital status and perceived health status. Finally, stress was associated with engaging in infrequent RSOD. Conclusions: Our finding associating daily smoking with risk alcohol intake specifically suggests the possibility of combining public health interventions for both. The study findings also indicate that education is a protective factor, further supporting the role of education as a major determinant of health. The significant provincial variation we found also point to the need to study this issue further and understand the links between provincial level policies and RSOD. Keywords: Risky single occasion drinking RSOD in Canada, Health policy, Stress, Smoking, Alcohol, Education, Social determinants, Provinces
Background From a public health perspective, alcohol consumption is a challenging issue to address. Controversy existed in the research community whether low levels of alcohol consumption have protective effects, and if these effects outweigh known harms; however, there is a growing consensus in the literature that the positive effects of alcohol consumption have been overestimated in the past [1–4]. Defining low-risk consumption has proved methodologically difficult, resulting in a variety of guidelines for low-risk alcohol intake across countries [5]. * Correspondence: [email protected] 1 School of Public Health, University of Saskatchewan, 104 Clinic Place, Saskatoon, SK S7N 2Z4, Canada Full list of author information is available at the end of the article
Likewise, alcohol misuse represents a wide spectrum of terms, from exceeding low-risk guidelines to alcohol dependence. A glossary of terms used in this article is outlined in Table 1. Despite variation in how different organizations define and convey low-risk drinking, it is clear that the misuse of alcohol, including risky single occasion drinking (RSOD), is associated with a number of negative health, social, and economic consequences [6, 7]. Direct health implications associated with alcohol misuse include dependency, liver cirrhosis, organ damage, diabetes, cardiovascular disease, and various types of cancer [7, 8]. Furthermore, impaired judgement, impaired driving ([9]), injury, suicide, and risky sexual behaviour may be prompted by high levels of alcohol consumption,
© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
Rafferty et al. Archives of Public Health (2017) 75:22
Page 2 of 11
Table 1 Glossary of Terms Associated with Alcohol Consumption Alcohol abuse
Is a pattern of drinking that results in harm to one’s health, interpersonal relationships, or ability to work [62].
Alcohol dependency
Dependency on alcohol, also known as alcohol addiction and alcoholism, is a chronic disease. The signs and symptoms for alcohol dependence include a strong craving for alcohol, continued use despite repeated physical, psychological, or interpersonal problems and the inability to limit drinking [62].
Binge drinking
A pattern of alcohol consumption that brings the blood alcohol concentration level to 0.08% or more. This pattern of drinking usually corresponds to 5 or more drinks on a single occasion for men or 4 or more drinks on a single occasion for women, generally within about 2 h [26].
Excessive alcohol use
Excessive drinking, or excessive alcohol use includes binge drinking, heavy drinking, any alcohol use by people under the minimum legal drinking age, and any alcohol use by pregnant women [63].
Heavy drinking
For men heavy drinking is typically defined as consuming 15 drinks or more per week. For women, heavy drinking is typically defined as consuming 8 drinks or more per week [63].
Heavy episodic drinking
Defined by the World Health Organization (WHO) as 60 or more grams of pure alcohol on at least one single occasion at least monthly [15].
Risky drinking
Women having more than 3 drinks or men having more than 4 drinks on any single occasion once per month or more often [64].
Risky single occasion drinking (RSOD)
Having X number of standard drinks or more (X+) on one occasion. This definition may vary across countries by number of drinks as well as grams of alcohol per drink [65]. This article uses 5 or more drinks regardless of sex to define RSOD, based on the CCHS classification, which is equivalent to consuming 70 g or more of pure alcohol on one single occasion.
suggesting there may be broader health and social repercussions [7, 10]. In Canada, the most recent comprehensive economic analysis of alcohol-related costs was conducted in 2006 using data from 2002, and estimated that a total of CAD 14.6 billion was spent that year on direct and indirect costs [11, 12]. These costs are associated with healthcare, law enforcement, and productivity losses [7, 12]. Direct healthcare costs alone accounted for CAD 3.3 billion in spending in 2002 [7, 12]. More recently in 2013, the costs of Fetal Alcohol Spectrum Disorder (FASD) in Canada alone totalled approximately CAD 1.8 billion dollars [13] In contrast, the societal and healthcare costs of excessive alcohol use in the United States have been estimated at USD 223.5 billion and 24.5 billion, respectively [14]. Worldwide, alcohol abuse accounted for approximately 3.3 million deaths and 139 million disability-adjusted life years (DALYS) due to injury and morbidity [15]. Inhabitants of the North American region drank 8.4 l of pure alcohol per capita in 2010, 35% higher than the world average (6.2L) and second only to the European region (10.9 L). Among current alcohol drinkers in the Americas, the prevalence of heavy episodic drinking is 22%, again second only to Europe (22.9%). In the United States, the prevalence of monthly binge drinking defined in the article as 5+ drinks for men, 4+ for women in one occasion is approximately 17% [16]. A substantial proportion of these alcohol-related harms are associated with populations who exceeded low-risk alcohol guidelines, which is determined by quantity and/or frequency of alcohol use [7, 14, 17]. As the frequency of RSOD increases, the likelihood of negative health and social consequences increases [7, 17]. In addition, there is some evidence from the United States
which indicates that moderate drinkers contributed to the majority of RSOD episodes ([18]). Research shows that a number of economic, cultural, and historical factors contribute to individuals’ drinking practices [1, 19]. Data from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and the National Survey on Drug Use and Health (NSDUH) demonstrated associations between early initiation of drinking (before the age of 21), age of 20–29 years, enrollment in college, being male and an increased engagement in RSOD, [1, 20]. However, it appears the gender gap is decreasing among younger cohorts [8]. In general, the factors that impact alcohol consumption have not been well explored within a Canadian context. Of particular interest may be how location of residence influences alcohol consumption in Canada, as provincial and territorial (P/T) jurisdiction over alcohol policy has created a patchwork of liquor regulations throughout the country [19, 21]. Studying provincial variations in alcohol consumption may provide insight into the impact of public policy, along with other cultural and socio-political differences, on RSOD. Furthermore, a deeper understanding of the risk factors that contribute to RSOD with respect to P/T may help guide relevant and informed alcohol related policies for each P/T. Although experts agree that alcohol consumption can lead to negative health, social and economic consequences, defining low-risk intake has proved challenging for researchers and organizations [5, 12, 22]. Both volume and patterns of alcohol use can lead to separate risks, and studies have varied in their assessment of risk, with some focused on dose–response curves, while others focused on alcohol-attributable fractions [5]. Grams of pure alcohol per standard drink varies widely
Rafferty et al. Archives of Public Health (2017) 75:22
worldwide and portion sizes served often differ from the standard drink [5]. These debates added to the complexity for P/T governments and non-profit organisations to determine Canada’s Low Risk Alcohol Drinking Guidelines and communicate them to the public. In 2011, the National Alcohol Strategy Working Group (NASWG) recommended that, based on the available evidence, no more than two drinks should be consumed on most days for women (28 g of ethanol) and no more than three a day for men (42 g of ethanol) [23–25]. Similarly, the guidelines recommend that over the duration of a week, women should consume less than 10 drinks and men less than 15 (140 and 210 g of pure alcohol, respectively) [23]. The CCSA defines risky drinking as “women having more than 3 drinks or for men more than 4 drinks on any single occasion once per month or more often” [23]. In contrast, the Canadian guidelines surrounding the definition of low-risk drinking are stricter compared to guidelines in the United States. For women, the National Institute on Abuse and Alcoholism (NIAA) [26] decrees that low-risk drinking consists of no more than 3 drinks per day and 7 per week (42 and 98 g of pure alcohol, respectively), whereas for men the guideline is 4 and 14 respectively (56 and 196 g of pure alcohol, respectively) [26]. European guidelines vary widely by country, and in response to this, recent practice principles from the Joint Action Reducing Alcohol Related Harm (RARHA) in Europe and the Center for Addiction and Mental Health (CAMH) have attempted to identify a standard definition of risk. They indicate that a level of alcohol intake of 10 g or less per day would result in an alcohol attributed death rate of below 1 in 100, and provide this as a suggested maximum for low risk drinking [27, 28]. This would equate with less than one standard drink per day in Canada, where one standard drink contains approximately 14 g of pure alcohol [24, 25]. The overall purpose of this study is to explore the pastyear prevalence of RSOD in Canada and the factors associated with any RSOD and frequency of RSOD in Canada. Understanding the underlying factors contributing to RSOD in Canada will help guide the development of more effective policy interventions to curtail high-risk consumption. The two research questions developed were: 1) What factors determine the likelihood of individuals engaging in any RSOD over the past 12 months? 2) What factors determine the likelihood of engaging in frequent RSOD? We defined infrequent RSOD as (past-year occurrence of drinking 5+ drinks (70+ grams alcohol) once a month or less) and frequent RSOD as (past-year occurrence of drinking 5+ drinks (70+ grams alcohol) more than once a month).
Page 3 of 11
Methods The Canadian Community Health Survey (CCHS) 2009–2010 annual component was used to conduct all the analyses in this paper ([29]). The sample size of this survey was 124,188. The response rate for the outcome variable of interest “How often in the past 12 months have you had 5 or more drinks on one occasion?” was 74.3%. Since logistic regression modeling uses listwise exclusion of missing values, the sample size of the regression models and descriptive statistics was 68,440. The sample was weighted using the survey weights provided by CCHS as instructed by Statistics Canada [30]. Descriptive statistics were conducted in SPSS Version 22.0 and regression modeling conducted using SAS 9.4 software. The alpha was set at 0.05. Dependent variables
The CCHS captured individual’s alcohol consumption through the original question “How often in the past 12 months have you had 5 or more drinks on one occasion?” R (18) [29]. As this is the only measure for alcohol consumption in the CCHS, we drew on the work of Thomas [19] and defined occasional any RSOD conservatively as having 5 or more drinks on one occasion in the past 12 months, infrequent RSOD as having 5 or more drinks on one occasion once or less than once a month and frequent RSOD as having 5 or more drinks on one occasion more than once a month [19]. In Canada, one standard drink contains approximately 14 g of pure alcohol, therefore RSOD in this case would be defined as having 70 g of alcohol in one sitting [24, 25]. Based on these definitions, we created two dependent variables: (1)RSOD which has two categories (binary outcome variable). ‘Yes’ if individual engaged in any RSOD in the past 12 months and ‘no’ if the individual did not engage in RSOD in the past 12 months. (2)Frequency of RSOD (multinomial outcome variable) which has three categories: i. No RSOD in the past 12 months ii. Infrequent RSOD: Over the past year, engaging in RSOD once a month or less iii. Frequent RSOD: Over the past year, engaging in RSOD more often than once a month Independent variables
Based on the relevant literature, we were able to identify independent variables likely associated with risky drinking, including age, sex, marital status, education status, income, employment, smoking status, self-perceived health, and self-perceived life stress [7, 31, 32]. As Thomas [19] identified, there is substantial provincial variation in alcohol consumption across Canada, and so
Rafferty et al. Archives of Public Health (2017) 75:22
we included the P/T variable as a geographic marker, as well as an indication of alcohol price and other regulatory policies. This comparison is possible as price (e.g., taxation) and regulation of alcohol differ by P/T. The P/ T variable also stands to represent other historical, socio-political and cultural factors that may be present within jurisdictions. Age groups were categorized based on Thomas et al. [19]. Employment status was grouped as “employed last week” and “unemployed last week” to see the effect of employment status on RSOD, and was categorized based on the CCHS question, “Are you an employee or self-employed?” Total household income was captured and analyzed in increments of CAD 20,000 from
